Wednesday, July 20, 2011

While my computer was writing to a 3½" floppy disk via the floppy controller on my motherboard, I pushed the sleep key, requesting S3 sleep. Right after that, I remembered how Windows cannot really be trusted when doing unusual things. I started to wonder if I'll see a bluescreen, but all I saw was sleep being delayed by lengthy floppy activity. When I came back, I was not too surprised to see a bluescreen. The source of the crash was a bit surprising however: usbser.sys had submitted an IRP that was already pending in the USB bus driver. I guess delays from the floppy driver triggered a bug in usbser.sys. This was failure bucket 0xFE_usbser!RestartNotifyRead+73. It was usbser.sys 6.1.7601.17514 (win7sp1_rtm.101119-1850), so this really is a component of Windows, and not a 3rd party driver.